Enhanced Photocatalytic Degradation and Mineralization of Furfural Using UVC/TiO 2

Titanium dioxide nanoparticles were immobilized on granular activated carbon (GAC) as a porous and low-density support for photocatalytic degradation of furfural. The TiO2/GAC composite was synthetized using the simple sol-gel method and fully characterized. The effects of the operational parameters of furfural concentration (200–700 mg/L), initial pH (2–12), TiO2/GAC composite dosage (1–3.5 g/L), and irradiation time (20–120 min) were studied. The synthetized TiO2/GAC composite exhibited a total pore volume of 0.13 cm3/g and specific surface area of 35.91 m2/g. Removal efficiency of up to 95% was observed at initial pH of 10, TiO2/GAC dosage of 2.5 g/L, irradiation time of 80 min, and initial furfural concentration of 500 mg/L. The photocatalyst could be reused at least four consecutive times with a mere 2% decrease in furfural removal efficiency. Mineralization efficiency of 94% was obtained within 80 min. Pseudo-first-order kinetics best fit the photocatalytic degradation of furfural under experimental conditions

Investigating the effect of point-of-use water treatment (POU) system on Urban Water Quality in IRAN: A systematic review

In many developing countries, insufficient water treatment forces the people to use the home point of use (POU) systems. A scientific review was conducted for all articles published on POU for Iranian cities. This study focuses on the effect of the POU systems on water quality. The related data were collected according to the inclusion and exclusion criteria and by searching. Supported the searched keywords with emphasis on the type of water treatment system and the type of incoming water, the obtained articles were reviewed. The qualitative data were collected employing a preferred reporting items for systematic reviews and Meta-analyzes (PRISMA) standard checklist. 544 article titles were found within the initial search with the keywords listed. Finally, after reviewing the knowledge and quality of the articles, 20 articles were eligible for systematic review. the most important number of articles were published between 2012 and 2021. In some cities, EC, TDS and total hardness were high, which reached the specified standard after leaving the POU systems. But since these systems reduce all parameters and are not selective, they greatly reduce the quantity of chlorine, fluoride and sometimes TDS and pH. As chlorine decreases, the quantity of microbial contamination in the effluent increases. By reducing the fluoride within the effluent, the health of the teeth and bones is compromised over time. Therefore, on time replacement of all filters is essential and consumers and operators of these systems should be trained enough in the field of water quality standards and guidelines

Life cycle assessment, a decision-making tool in wastewater treatment systems: a case study wastewater treatment plant of Ahvaz, Iran

Abstract The evaluation of environmental implications associated with wastewater treatment plants and developing strategies for reusing wastewater with minimal harm to the environment and human communities is critical. This study investigates the environmental impacts of Ahvaz’s wastewater treatment plant using life cycle assessment, employing SimaPro®9.0.0 software for two scenarios. The first scenario represents the current state of the plant, while the second considers reusing treated effluent in farms. This examination can lead to modifications within existing systems or selection of the best alternative treatment option, ultimately reducing potential environmental impacts. The CML2001 method identified human toxicity and global warming (4.29 × 1013 and 3.67 × 1013, respectively), while the EcoIndicator99 method indicated ecotoxicity and carcinogens (5.2 × 10−13 and 2.82 × 10−13, respectively) as the highest contributors to negative environmental impact per 1 m3 treated effluent. The results demonstrate that although using treated sludge and effluent in agriculture conserves a significant amount of water, phosphorus, and nitrogen, it caused significant adverse impacts due to heavy metals present in the effluent and sludge. Additionally, the methane produced by sludge treatment, digestion, and disposal processes had the most harmful impact on global warming (0.577 (65%) in the CML2001 method). Comparing the two scenarios demonstrates that reusing effluent in farm irrigation is a more environmentally friendly technique, particularly in terms of eutrophication

Potential of Producing Compost from Source-Separated Municipal Organic Waste (A Case Study in Shiraz, Iran)

Developing countries face serious environmental, social and economic challenges in managing different types of organic waste. Proper treatment strategies should be adopted by solid waste management systems in order to address these concerns. Among all of the treatment options for organic waste, composting is the most approved method as an effective strategy to divert solid waste from landfills. This experimental research aimed to examine the potential of producing compost from source-separated municipal organic waste in Shiraz, Iran. Market waste (fruits and vegetables) and garden waste (plant residues) were used as the raw input materials. They were subjected to the windrow pile composting method in an open site area. The process was monitored against several physical, chemical and biological parameters. In-situ measurements (temperature and moisture content) were carried out on a daily basis. Sampling and lab analyses were conducted over the period of the biological treatment. The final product was of acceptable moisture and nutrient levels, pH, Electrical Conductivity (EC), and Carbon/Nitrogen ratio. All of the analyzed compost samples had lower concentrations of heavy metals than the Iranian and German standards. Overall, the results obtained revealed that composting is a promising method for municipal organic waste treatment. The findings also imply the effectiveness of the source-separation collection method in the production of high-quality compost